Emergence of ciprofloxacin resistance in Escherichia coli isolates after widespread use of fluoroquinolones.

The evolution (from 1990 to 1996) of fluoroquinolone consumption and resistance and the current patterns of fluoroquinolone usage were examined in a 250-bed community hospital in Spain. Fluoroquinolone consumption increased from 1392 g in 1990 to 3203 g in 1996 (p < 0.05). A significant increase in ciprofloxacin resistance was observed in Escherichia coli isolated from urine samples (from 3 to 20%, p < 0.00001), but not in those E. coli isolated from blood or other sample cultures. In 69 randomly selected clinical charts, fluoroquinolone was used as prophylaxis, empirical therapy, and specific directed therapy in 20%, 65%, and 15%, respectively. Evaluation of quinolone indication was: first choice agents (29%), alternative agents (49%), experimental agents (4.3%) and, agents with no role (1.4%). Our study shows that the increase in the use of fluoroquinolones is associated with the emergence of ciprofloxacin-resistant E. coli from urinary tract sources. Based on their indications, current quinolone usage can be greatly reduced.